Geotechnical Properties of Compacted Silty Clay Mixed With Different Sludge Contents

The presence of organic matter in soil may cause different problems depending on many factors such as type and contents of these organic materials. A testing program was carried out to study the geotechnical properties and the behavior of organic matter obtained by the addition of a sludge material brought from a sewerage treatment plant.The tests include classification, chemical, compaction, compressibility and shear strength tests. Based on the results, several conclusions have been obtained. Both liquid and plastic limits increased with increasing organic matter. Regarding compaction test, it can be noticed that both maximum dry density and optimum moisture content slightly decreased with increasing organic contents then tends to increase.Through the observation of shear strength test results, qu and cu increased with increasing organic matter contents and then tends to decrease in similar manner to the density water relation of compaction test. Regarding compressibility, organic content, water content, void ratio and arrangement of soil particles are dominant factors controlling this property. The compression behavior of organic soils varies from the compression behavior of other types of soils in two ways, first the compression of organic soils is much larger and second, the creep or secondary compression plays an important role in determining the total settlement as shown in developing a unique relationship for organic soils

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ABSTRACT The experimental work of this study deals with the problem of buried UPVC pipe in sand with different pipe responses subjected to incremental static loading where the backfill densities changed (loose, medium, and dense with different burial depth (1.5 d,2 d, and 3d). The objectives of the current study are to study the effect of changing the buried depth on the behavior of a buried flexible pipe in a sand soil through experimental model. It was found that the effect of the applied surface load on the crown strain is reduced by increasing the burial depth by about 19.6% when the embedment depth changes from 1.5 d to 2 d and 29.4% when it changes from 1.5 d to 3 d in loose sand. While these percents become to 13.1% and 32.2% in the medium sand and to 21.4% and 40% in the dense sand. It is concluded from these results that the increase in the depth of burial and sand density sponsor by reducing the strain on the perimeter of the pipe and thus the pipe is protected from the distortions that lead to breakage the pipe

TREATMENT OF COLLAPSIBILITY OF GYPSEOUS SOIL

A series of double odometer tests are conducted to study the compressibility and collapse of gypseous soil taken from west of Baghdad governorate. The gypsum content of the soil used is nearly 25%. Four different types of additives are selected to reduce the collapse strain of this soil. These additives are cement, bentonite, calicium chloride and silicagel. An adequate reducing in the compressibility and collapsibility was obtained especially when the cement is used

California Bearing Ratio of Some Iraqi Dune Soils

   This paper contains the results of CBR tests that performed on compacted samples of real dune sand (cohesionless sand grains) and pseudo dune sand which is a mixture of sand sized  aggregate of  clay and silt. The effect of compaction and soaking on the bearing values are included in this research.    The results indicated that the compacted real dune sands have high strength and low sensitivity to soaking. The 5 mm penetration of CBR of this soil is higher than that of 2.5 mm. On the other hand, the loss of strength due to soaking can be quite considerable in compacted pseudo dune sands. The CBR values obtained at 2.5 mm and 5 mm penetration are approximately equal in pseudo dune sands